arXiv subjects

S. Gourlay

Publications and source records attributed to S. Gourlay.

10 recordsLinked to original sources

arXiv2025

Magnet R&D for the Muon Collider

A proton-driven Muon Collider, in the configuration that has resulted from the efforts of the International Muon Collider Collaboration (IMCC), poses multiple and exceptional magnet system challenges. Addressing these challenges will require a focused effort to advance accelerator magnet technology well beyond the present state of the art, including activities that have not previously been supported by High Energy Physics (HEP) programs, but are synergic with them. This proposal presents the motivation for a directed effort focusing on the development and testing of small- and full-scale magnet prototypes, ultimately culminating in their validation under collider-relevant conditions. This document summarizes technology status, challenges, and development targets, and outlines a detailed plan with staged milestones to advance the technological readiness of magnet systems, bringing the realization of the Muon Collider closer to reality. The total resources to achieve this goal are estimated at 82.5 MCHF and 414 FTE y over ten years, of which 39 MCHF and 199 FTE y are engaged over the first five years. Reaching the desired performance with sustainable technology will depend greatly on exploiting the potential of High Temperature Superconductors (HTS). Mainly because of this, the R&D proposed here has significant potential to broadly impact HEP and its other circular collider considerations such as the FCC-hh, as well as other fields of scientific and societal application, e.g. science in high magnetic fields, NMR and MRI, fusion and other power and mobility applications.

physics.acc-ph↗

arXiv2025

Magnet R&D for the Muon Collider -- European Strategy Input

The Muon Collider, proposed under the International Muon Collider Collaboration (IMCC), represents a groundbreaking advancement in circular collider technology. By using muons instead of protons or electrons, this collider has the potential of unprecedented discovery reach, luminosity, and compact design, significantly increasing energy efficiency, reducing environmental impact and improving sustainability. However, achieving this vision necessitates overcoming unique and extreme challenges in superconducting magnet technology. This document summarizes the state of the art, challenges, and the proposed R&D roadmap for developing the next generation of superconducting magnet systems crucial for the Muon Collider over the next ten years. The goal is to advance accelerator magnet technology beyond current limits, with a special focus on High-Temperature Superconductors (HTS) materials for high-field and high-temperature applications. This note is a concise summary of the extensive proposal [BOT-2025] which we refer to for detailed referencing and as supporting material. We focus here on the technology gap to be filled by the proposed R&D, the structure and objectives of the proposed R&D, and provide the resource estimate for the next ten years.

physics.acc-ph↗

arXiv2023

Challenges and Lessons Learned from fabrication, testing and analysis of eight MQXFA Low Beta Quadrupole magnets for HL-LHC

By the end of October 2022, the US HL-LHC Accelerator Upgrade Project (AUP) had completed fabrication of ten MQXFA magnets and tested eight of them. The MQXFA magnets are the low beta quadrupole magnets to be used in the Q1 and Q3 Inner Triplet elements of the High Luminosity LHC. This AUP effort is shared by BNL, Fermilab, and LBNL, with strand verification tests at NHMFL. An important step of the AUP QA plan is the testing of MQXFA magnets in a vertical cryostat at BNL. The acceptance criteria that could be tested at BNL were all met by the first four production magnets (MQXFA03-MQXFA06). Subsequently, two magnets (MQXFA07 and MQXFA08) did not meet some criteria and were disassembled. Lessons learned during the disassembly of MQXFA07 caused a revision to the assembly specifications that were used for MQXFA10 and subsequent magnets. In this paper, we present a summary of: 1) the fabrication and test data of all the MQXFA magnets; 2) the analysis of MQXFA07/A08 test results with characterization of the limiting mechanism; 3) the outcome of the investigation, including the lessons learned during MQXFA07 disassembly; and 4) the finite element analysis correlating observations with test performance.

physics.acc-ph↗

arXiv2022

Snowmass'21 Accelerator Frontier Report

In 2020-2022, extensive discussions and deliberations have taken place in corresponding topical working groups of the Snowmass Accelerator Frontier (AF) and in numerous joint meetings with other Frontiers, Snowmass-wide meetings, a series of Colloquium-style Agoras, cross-Frontier Forums on muon and electron-positron colliders and the collider Implementation Task Force (ITF). The outcomes of these activities are summarized in this Accelerator Frontier report.

physics.acc-ph↗

arXiv2022

U.S. National Accelerator R\&D Program on Future Colliders

Future colliders are an essential component of a strategic vision for particle physics. Conceptual studies and technical developments for several exciting future collider options are underway internationally. In order to realize a future collider, a concerted accelerator R\&D program is required. The U.S. HEP accelerator R\&D program currently has no direct effort in collider-specific R\&D area. This shortcoming greatly compromises the U.S. leadership role in accelerator and particle physics. In this white paper, we propose a new national accelerator R\&D program on future colliders and outline the important characteristics of such a program.

physics.acc-ph↗

arXiv2022

A Strategic Approach to Advance Magnet Technology for Next Generation Colliders

Colliders are built on a foundation of superconducting magnet technology that provides strong dipole magnets to maintain the beam orbit and strong focusing magnets to enable the extraordinary luminosity required to probe physics at the energy frontier. The dipole magnet strength plays a critical role in dictating the energy reach of a collider, and the superconducting magnets are arguably the dominant cost driver for future collider facilities. As the community considers opportunities to explore new energy frontiers, the importance of advanced magnet technology - both in terms of magnet performance and in the magnet technology's potential for cost reduction - is evident, as the technology status is essential for informed decisions on targets for physics reach and facility feasibility.

physics.acc-ph↗

arXiv2019

First particle-by-particle measurement of emittance in the Muon Ionization Cooling Experiment

The Muon Ionization Cooling Experiment (MICE) collaboration seeks to demonstrate the feasibility of ionization cooling, the technique by which it is proposed to cool the muon beam at a future neutrino factory or muon collider. The emittance is measured from an ensemble of muons assembled from those that pass through the experiment. A pure muon ensemble is selected using a particle-identification system that can reject efficiently both pions and electrons. The position and momentum of each muon are measured using a high-precision scintillating-fibre tracker in a 4\,T solenoidal magnetic field. This paper presents the techniques used to reconstruct the phase-space distributions and reports the first particle-by-particle measurement of the emittance of the MICE Muon Beam as a function of muon-beam momentum.

physics.acc-ph↗

arXiv2016

Pion contamination in the MICE muon beam

The international Muon Ionization Cooling Experiment (MICE) will perform a systematic investigation of ionization cooling with muon beams of momentum between 140 and 240\,MeV/c at the Rutherford Appleton Laboratory ISIS facility. The measurement of ionization cooling in MICE relies on the selection of a pure sample of muons that traverse the experiment. To make this selection, the MICE Muon Beam is designed to deliver a beam of muons with less than $\sim$1\% contamination. To make the final muon selection, MICE employs a particle-identification (PID) system upstream and downstream of the cooling cell. The PID system includes time-of-flight hodoscopes, threshold-Cherenkov counters and calorimetry. The upper limit for the pion contamination measured in this paper is $f_π< 1.4\%$ at 90\% C.L., including systematic uncertainties. Therefore, the MICE Muon Beam is able to meet the stringent pion-contamination requirements of the study of ionization cooling.

physics.ins-det↗

arXiv2015

Electron-Muon Ranger: performance in the MICE Muon Beam

The Muon Ionization Cooling Experiment (MICE) will perform a detailed study of ionization cooling to evaluate the feasibility of the technique. To carry out this program, MICE requires an efficient particle-identification (PID) system to identify muons. The Electron-Muon Ranger (EMR) is a fully-active tracking-calorimeter that forms part of the PID system and tags muons that traverse the cooling channel without decaying. The detector is capable of identifying electrons with an efficiency of 98.6%, providing a purity for the MICE beam that exceeds 99.8%. The EMR also proved to be a powerful tool for the reconstruction of muon momenta in the range 100-280 MeV/$c$.

physics.ins-det↗

arXiv2013

Characterisation of the muon beams for the Muon Ionisation Cooling Experiment

A novel single-particle technique to measure emittance has been developed and used to characterise seventeen different muon beams for the Muon Ionisation Cooling Experiment (MICE). The muon beams, whose mean momenta vary from 171 to 281 MeV/c, have emittances of approximately 1.5--2.3 πmm-rad horizontally and 0.6--1.0 πmm-rad vertically, a horizontal dispersion of 90--190 mm and momentum spreads of about 25 MeV/c. There is reasonable agreement between the measured parameters of the beams and the results of simulations. The beams are found to meet the requirements of MICE.

physics.acc-ph↗